Mike - that streaking looks really good, nice technique there.
I'm no WW1 expert, but have spent more than a few nights reading some of the plethora of threads at the Aerodrome forum on Fokker streaking. There is a lot written there, much discussion and sometimes very hotly debated opinions.
Of what is certain is the streaking was applied by hand brush at the factory. Some have suggested an 8 inch wide brush, but I forget how they came to this conclusion. There is a photo from a factory of a worker with a number of fokker wings on a rack, drying perhaps. There seems to be a conscious effort that the applied wing surface streaking was at an angle of about one to one and one half ribs apart.
What is hotly debated is the surface colour before applied streaking. Most seem to be of the opinion it was either plain or treated canvas (but not coloured).
The colour of the streaking is another proverbially can of worms. There are three proposed methods I have read about.
The simplest is the olive(?) was stroked on with a back and forth motion till the paint ran out, then the brush was reloaded and contined from the last applied stroke.
Second method was to have three buckets of the same paint colour, but each one was thinned more than the previous.
Thirdly, there was two or even three colours of paint used.
regards,
Jack